The fishing pole of the future might just be a robot. Researchers at MIT have created a soft, transparent device that’s capable of catching and releasing a live goldfish, LiveScience reports. Described in a study in Nature Communications, it’s made of a hydrogel that can change shape when water is pumped into or out of it.

The researchers created three different types of hydrogel robots to test the material’s capabilities, each made of small tubes inspired by glass eels—a transparent, juvenile eel. One robot was shaped like an appendage of a claw machine; the other, like a pool noodle; the third, like a fish’s fin that flaps back and forth. The noodle-shaped hydrogel robot was capable of enough force to kick a ball underwater, while the claw-shaped robot was quick enough to catch a live fish—and gentle enough not to squish it in the process.

Because the hydrogel is mostly water, and the robots are powered by water, they could be made invisible in the future. But they could also be used for less-than-sneaky purposes, like to assist surgeons. They’re wet and soft, so they could be more delicate than human hands in manipulating organs and tissues during a procedure, the researchers suggest in a statement.

[h/t LiveScience]

Teaser image courtesy Hyunwoo Yuk/MIT Soft Active Materials Lab